Solanum echegarayi Hieron., Bol. Acad. Nac. Cienc. (Cordoba) 9: 58. 1881.

Knapp, Sandra, Saerkinen, Tiina & Barboza, Gloria E., 2023, A revision of the South American species of the Morelloid clade (Solanum L., Solanaceae), PhytoKeys 231, pp. 1-342 : 1

15. Solanum echegarayi Hieron., Bol. Acad. Nac. Cienc. (Cordoba) 9: 58. 1881.

Figs 47 , 48

Solanum juncalense Reiche, Anales Univ. Chile 124: 459. 1909. Type. Chile. Región VII (Valparaiso): [Los Andes] Juncal [protologue: "Cordilleras de la provincia de Aconcagua, Juncal"], 15 Jan, O. Buchtien 150 (no herbaria or collector cited; neotype, designated here: SGO [SGO000004574]).

Solanum hastatilobum Bitter, Repert. Spec. Nov. Regni Veg. 13: 246. 1912. Type. Argentina. San Luis: Quebrada del Salado, cerca de Bebida de las Varas, 9 Mar 1882, C. Galander s.n. (holotype: B [destroyed]; lectotype, designated by Barboza et al. 2103, pg. 249: CORD [CORD00004221]).

Solanum juncalense Reiche subsp. aconcaguae Bitter, Repert. Spec. Nov. Regni Veg. 12: 156. 1913. Type. Argentina. Mendoza: Dpto. Las Heras, "Puente del Inca, in viciniis montis Aconcagua", 23 Feb 1903, G.A. Malme 2956 (holotype: S [acc. # 10-15685]; isotypes: G [G00343486], MO [MO-256207, acc. # 2741560], US [00027638, acc. # 1572914]).

Solanum hastatilobum Bitter subsp. brachyphyllum Bitter, Repert. Spec. Nov. Regni Veg. 13: 171. 1914. Type. Argentina. San Juan: Dpto. Angaco: Cumbre del Gato, Cerro Pico de Palo, T. Stuckert 7029 (lectotype, designated by Barboza et al. 2103, pg. 249: G [G00343383]).

Solanum glaberrimum C.V.Morton, Revis. Argentine Sp. Solanum 82. 1976. Type. Argentina. La Rioja: Quebrada de la Troya, 21 Feb 1941, G. Covas 1235 (holotype: GH [00062989]; isotypes: LP [LP010903, acc. # 048953], NY [00076825], US [00027581, acc. # 2639762, fragment of GH holotype]).

Type.

Argentina. San Juan: Salida de la Quebrada del Leoncito , Jan 1876, S. Echegaray s.n. (holotype: CORD [CORD00004197]; isotype: US [00027559, acc. # 2678279]).

Description.

Sprawling perennial herbs from woody rhizomes (underground rootstocks), prostrate to semi-erect, 0.1-0.5 m high, woody at the base, extremely variable in size depending on season of collection. Stems angled or slightly winged from the decurrent leaf bases, completely glabrous to sparsely and minutely pubescent with eglandular antrorse 1-2-celled simple uniseriate trichomes 0.1-0.2 mm long, these more like papillae, soon deciduous and the stems glabrescent; new growth glabrous to sparely papillate like the stems; bark of older stems pale tan or brown. Sympodial units difoliate, the leaves not geminate. Leaves simple and usually shallowly lobed, the blades (0.5)1.5-4.5 cm long, (0.3)0.5-2.2 cm wide, elliptic to ovate, widest at the middle or in the lower half, thick, fleshy and rubbery in texture in live plants, concolorous, extremely variable on individual plants and through the growing season; adaxial and abaxial surfaces glabrous, occasionally with a few scattered eglandular 1-2-celled simple uniseriate trichomes on the midrib; principal veins 3-5 pairs, often not visible in live or dried plants, if visible drying yellowish cream on herbarium specimens; base attenuate to truncate, always decurrent onto the petiole with a wing of leaf tissue; margins lobed, the lobes deltate, apically acute, often basiscopic (pointing towards stem), the sinuses reaching 1/4 to halfway to the midrib, revolute; apex acute; petiole 0.3-1.1 cm long, always winged with leaf tissue, glabrous or minutely puberulent with antrorse eglandular papillae. Inflorescences internodal or almost opposite the leaves, unbranched, (1)1.5-6.5 cm long, with 4-10 flowers, usually only 1-2 open at a time, glabrous or minutely puberulent with antrorse papillae like the rest of the plant; peduncle 0.5-2 cm long; pedicels 0.7-1.1 cm long, ca. 0.75 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, tapering, glabrous or minutely papillate, articulated at the base; pedicel scars in pairs, each pair spaced ca. 2.5 mm apart. Buds ellipsoid, the corolla included in the calyx tube until just before anthesis due to rapid expansion of buds. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1.5-2 mm long, conical, the lobes 2.5-4(5) mm long, 1-1.5 mm wide, long-triangular, rigid and fleshy, glabrous or minutely puberulent-papillate like the rest of the plant. Corolla 1.4-2 cm in diameter, white or pale violet, with a greenish yellow central eye edged with paler yellow, stellate, lobed ca. halfway to the base, the lobes 5-6 mm long, 2.5-4 mm wide, reflexed to spreading at anthesis, glabrous adaxially, glabrous or minutely puberulent abaxially with mixed eglandular simple uniseriate trichomes and papillae along the midvein, densely papillate at tips and margins. Stamens equal; filament tube less than 0.2 mm; free portion of the filaments ca. 1 mm long, glabrous or with a few eglandular tangled simple uniseriate trichomes to 0.5 mm long adaxially; anthers 4.5-5 mm long, 1-1.5 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 8.5-9 mm long, straight, exserted beyond the anther cone, minutely papillate in the lower half within the anther cone; stigma capitate, the surface minutely papillate, green in live plants. Fruit a globose berry, 0.7-1.2 cm in diameter, green or purplish green at maturity, the pericarp thin, shiny, opaque or slightly translucent, glabrous; fruiting pedicels 1-1.4 cm long, ca. 0.7 mm in diameter at the base, ca. 2 mm in diameter at the apex, spreading, not markedly woody, not persistent; fruiting calyx not accrescent, the lobes 2.5-4 mm long, 1-1.5 mm wide, spreading and slightly reflexed at the tips, fleshy and rubbery in live plants, somewhat woody in dried specimens. Seeds (5)10-20 per berry, ca. 2 mm long, 1.5-2 mm wide, reddish brown, teardrop shaped, the surfaces minutely pitted, the testal cells sinuate in outline in the seed centre, rectangular at the margins. Stone cells 10-12 per berry, 1-1.5 mm in diameter, pale creamy white. Chromosome number: n = 12 ( Moscone 1992, voucher Barboza 62; Moyetta et al. 2013, voucher Chiapella et al. 2630, as S. hastatilobum ).

Distribution

(Fig. 49 ). Solanum echegarayi occurs in the Andes of central Argentina (Provs. Catamarca, Córdoba, La Rioja, Mendoza, Salta, San Juan, San Luis) and adjacent Chile ( Región V [ Valparaíso]).

Ecology and habitat.

Solanum echegarayi grows in dry, scrubby habitats, usually at high elevation, and in open rocky areas, often where little other vegetation occurs, from 650 to 4,200 m elevation.

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 352,787 km2 [LC]; AOO = 408 km2 [EN]. Solanum echegarayi is widespread along the Andes and occurs in disturbed habitats. It is found in several protected areas throughout its range in Argentina (e.g., Parque Nacional Talampaya, Parque Provincial Volcán Tupungato, Parque Nacional El Leoncito).

Discussion.

Solanum echegarayi is a fleshy, almost succulent plant with deep woody rhizomes from which new shoots arise every growing season. It is a member of the Episarcophyllum clade ( Särkinen et al. 2015b) together with S. riojense and S. sinuatirecurvum , but not related to S. caesium which has previously ( Del Vitto and Petenatti 1999) been thought to have affinities to these taxa ( Gagnon et al. 2022). All species of the Episarcophyllum clade are perennial herbs with woody underground rhizomes and occur in dry habitats in Argentina and neighbouring Chile, generally above 2,000 m elevation. The species all have slightly thick and fleshy leaves that appear succulent when compared to other species of the Morelloid clade.

Solanum echegarayi and S. riojense have long been confused due to a mix-up of type specimens (see below). Solanum echegarayi differs from S. riojense in its lack of cobwebby, tangled trichomes and in its sharply pointed rather than rounded calyx lobe apices. Solanum sinuatirecurvum also has cobwebby trichomes and differs from S. echegarayi in its much larger berries (more than 1 cm in diameter versus usually less than 1 cm in diameter) with a yellow, leathery pericarp rather than a green to greenish purple, somewhat translucent pericarp.

Solanum echegarayi is very variable depending upon when in the growing season the plant is collected; plants from early in the season are quite small and can look markedly different from those collected later in the season. In addition, specimens are often collected without the deep rhizomes, and so have the appearance of ephemeral annuals. Plants arise from deep underground stems (see Figs 2C , 48B ) and the junction of vegetative shoots and rhizomes is quite fragile. Characters used to distinguish the species here recognised as synonyms of S. echegarayi that were regarded as distinct taxa by Del Vitto and Petenatti (1999) overlap broadly across the species range; plants from northern part of the range from lower elevations (described as S. hastatilobatum ) tend to have smaller fruits that are green or purple and more hastate leaves, but all intermediate variations occur (for example, the collections Barboza et al. 3447, 3450 from high elevation in La Rioja Province match these plants to some degree). The highest degree of variation occurs in the Province of San Juan, where intensive study of climatic and environmental conditions will prove useful in untangling patterns of vegetative variation. Molecular sequence data suggest there is some regional variation in S. echegarayi ( Gagnon et al. 2022) but further sampling of all three species in this small clade (e.g., S. echegarayi , S. riojense , S. sinuatirecurvum ) will be necessary to confirm these results.

Morton (1976) lectotypified S. echegarayi with a specimen in CORD (CORD00012856) labelled "Echegaray 472", indicating the type in B was destroyed. Hieronymus used only specimens at CORD in his description (as clearly noted in the introduction to his catalogue of Echegaray’s collections; Hieronymus 1881); Morton’s (1976) lectotypification is thus superfluous. In addition, the specimen selected by Morton (1976) is densely pubescent with cobwebby hairs on the new growth and does not match the protologue, where the plant is described as completely glabrous; this specimen is likely a label mix-up for Hieronymous & Neiderlein 472, a syntype of S. riojense (see discussion under S. riojense ). The sheets labelled "Echegaray 472" at CORD and SI (CORD [CORD00012856], SI [003309]) are therefore excluded from consideration as type material of S. echegarayi .

Solanum juncalense was described from material from "Cordilleras de la provincia de Aconcagua (Juncal, 2,200 m)", with no collector or herbarium cited. A specimen in SGO (SGO000004574) from [Nevado] Juncal and the same elevation (Buchtien 150) and annotated "S. juncalense R" is almost certainly original material and is here selected as the neotype.

Figures

Figure 2. Representative habits and leaves of South American morelloids A prostrate annual herbs (S. weddellii) B large lax shrubs (S. aloysiifolium) C roots forming along a creeping stem (S. juninense) D spinose processes on stems of many species (S. huayavillense) E glandular trichomes found in some members of the clade (S. glandulosipilosum) F dendritic / branched trichomes found in S. pallidum G regularly 3 - lobed leaves in S. palitans H highly variable leaves along a single stem in S. salicifolium (A Saerkinen et al. 4038 B Barboza et al. 3505 C Saerkinen et al. 4754 D Barboza et al. 3536 E Barboza et al. 3520 F Saerkinen et al. 4010 G Atchison & Gagnon 25 H Barboza et al. 3473). Photos by S. Knapp, G. Atchison, and T. Saerkinen.

Figure 47. Solanum echegarayi A flowering and fruiting branch B flower C calyx D dissected flower E stamen, dorsal view F stamen, ventral view G gynoecium H fruit I seed (A-I Biurrun et al. 5038). Illustration by M. Moreno. Previously published in Barboza et al. (2013: 249), as S. hastatilobum.

Figure 48. Solanum echegarayi A habit B underground woody rhizomes C flowers at anthesis D immature and mature fruits (A, C, D Barboza et al. 4783 B Knapp et al. 10540). Photos by G. E. Barboza and S. Knapp.

Figure 49. Distribution map of Solanum echegarayi.